Kickless welding cables and more particularly air-cooled kickless cables have been utilized for years. Such cables normally comprises two spirally wound sets, one positive and one negative, of cable conductors or ropes with a spider separator therebetween, such ropes being within a cover and connected at each end to a termination which comprises respective machined plates separated by a dielectric gasket. The interconnection between the terminations and the ropes normally involves manual operation such as a torch silver solder or brazing operation. Such prior art connections are thus normally quite labor intensive and subject to normal labor intensive defects. Moreover, when exotic materials are employed such as silver, this adds considerably to the cost. Also, because the termination-to-cable connection is subject to considerable stress during use, such connection may come apart during use resulting in low service life for the entire cable as a result of one faulty connection. The use of special soldering or brazing compositions, etc., can result in a higher resistance connection, particularly if fluxes or compositions other than silver or platinum are used, assuming the parts are made of copper. Higher resistances increase power losses and reduce efficiency. They also increase operating temperatures which further reduces the service life. Thus, there is a need for a low resistance cable termination connection in such air cooled cables which will provide long service life, such low resistance, and which can be manufactured at low cost.
Press welding is a process most commonly used in the formation of bus bars or other laminations. The work to be press welded is positioned between the conductive electrodes of a press welder. The electrodes usually are graphite blocks movable with respect to each other, usually by the operation of pneumatic cylinders. As the name implies, substantial pressure may be generated as well as a very high heat. The temperature and pressure are carefully controlled and partial welding fusion does take place among the parts between the electrodes. However, excess temperature and pressure can ruin the part. A properly press welded part has an electrical resistance the equivalent of a solid part, and provides a strong connection. Examples of press welding may be seen in prior U.S. Pat. Nos. 4,640,982 and 4,455,659.
U.S. Pat. No. 4,640,982 illustrates press welding used to form a termination in a two rope DC kickless water cooled cable using a specially formed D-clip on the end of each of the two ropes to fit with a specially machined termination allowing for water passages therethrough. Air cooled kickless cables, however, employ sets of positive and negative stranded ropes. A typical number would be six, with two sets of three. Some even use eight with two sets of four. Because of the large number of ropes cables, the need for relatively flat surfaces avoiding pressure concentrations, and the need for special rope orientations, multi-stranded rope or cable termination are difficult to form. It would accordingly be desirable if press welding techniques could be applied to multi-rope air cooled kickless cables providing a lower cost, longer life, and more efficient cable.
To the accomplishment of the foregoing and related ends the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principles of the invention may be employed.